1. Field of the Invention
This invention generally relates to controlling multiple bicycle operating characteristics. More specifically, the present invention relates to various features of an apparatus for controlling multiple bicycle operating characteristics and in particular, a bicycle derailleur.
2. Background Information
Bicycles have several operating components. For example, a bicycle transmission may comprise a plurality of front sprockets and a plurality of rear sprockets, wherein the plurality of front sprockets are mounted for rotation with the pedals, and the plurality of rear sprockets are mounted for rotation with the rear wheel. To change the gear ratio of the bicycle transmission, a front derailleur switches a chain to engage the various front sprockets, and a rear derailleur switches the chain to engage the various rear sprockets. Because the length of chain needed to engage a particular combination of front and rear sprockets changes depending upon the chosen sprocket combination, the chain must be long enough to engage the largest front sprocket and the largest rear sprocket, and some mechanism must be provided to take up the slack in the chain when the chain engages a smaller sprocket combination. Conventionally, the rear derailleur is provided with a chain guide that includes an upper guide sprocket and a lower tension sprocket, and the chain guide is spring-biased to rotate to take up the slack in the chain.
When the bicycle is ridden over rough terrain, the resulting shocks and vibrations may overcome the biasing force of the chain guide spring, and the chain guide may rotate in the chain loosening direction. Such undesirable rotation increases the risk that the chain derails from the currently-engaged sprocket and/or becomes caught between adjacent sprockets. To overcome such problems, various motion damping mechanisms for the chain guide have been developed. For example, U.S. Patent Application Publication No. 2012/0083371 titled “Bicycle Derailleur With Rotation Resistance” discloses a bicycle derailleur that comprises a base member, a movable member movably coupled to the base member, and a chain guide coupled to the movable member for rotation around a rotational axis. A resistance applying element applies resistance to rotational movement of the chain guide, and a resistance control element is operatively coupled to the resistance applying element so that the resistance applying element applies different first and second resistances to rotational movement of the chain guide when the resistance control element is disposed in respective first and second positions.
Some bicycles include front and/or rear suspension elements. The front suspension element typically comprises a pair of shock absorbers that form opposite portions of the legs of the front wheel fork, and the rear suspension element typically comprises a shock absorber with one end mounted to the front portion of the frame and another end mounted to a pivoting rear swing arm that supports the rear wheel. In any case, the shock absorber usually comprises an outer tubular suspension member and an axially telescoping inner tubular suspension member. A piston has an outer peripheral surface that sealingly and slidably engages the inner peripheral surface of the inner tubular suspension member to form a compression chamber in which a compressible fluid such as air is disposed. The piston is coupled to the outer tubular suspension member by a piston rod. Some shock absorbers include separate chambers disposed on opposite sides of the piston so that further operating parameters, such as ride height or stroke, may be controlled.
Some shock absorbers are constructed to allow the rider to vary several operating parameters to accommodate varying riding conditions. Such parameters include spring preload (for shock absorbers that use a coil spring), compression damping (to control the rate of shock absorber retraction), rebound damping (to control the rate of shock absorber extension), platform damping (to damp oscillation of the shock absorber caused by pedaling forces), cylinder pressure, cylinder volume, and lockout (the ability to turn the normal shock absorbing function on and off).
Bicycles usually also include adjustable seats. A typical bicycle seat comprises a saddle mounted to a seat post. The seat post is dimensioned to be inserted into a seat tube of the bicycle frame, and a clamp is used to clamp the seat tube around the seat post and thereby hold the saddle at a desired height. Some bicycles include an electric motor with a gear that engages gear teeth on the seat post in order to electrically adjust the saddle height and maintain the saddle at a desired height.